The Samsung 9100 Pro 8TB wins in 6 out of 7 comparable specs. Its biggest advantage is Endurance (TBW) (433% better).
WD Blue SN5000 2TB wins in 1 spec (MSRP: 90% better).
Recommendation
Choose 9100 Pro 8TB if you want the best overall performance — especially endurance (tbw).
Choose WD Blue SN5000 2TB if msrp matters more to you.